Subject: Western Pacific: Synoptic Discussion For The Marianas

From: LDM Weather <[email-masked]>
Date: Sun, 17 Oct 2010 02:30:56 -0500

585 
FXPQ60 PGUM 170730
AFDPQ 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
530 PM CHST SUN OCT 17 2010

.SYNOPSIS...
AN UPPER-LEVEL TROUGH WAS MOVING OVER THE AREA THIS AFTERNOON. AN
UPPER-LEVEL LOW IS LOCATED IN THE TROUGH NEAR 17N148E...OR JUST
SOUTHEAST OF PAGAN. THE LOW AND TROUGH ARE MOVING WEST. RADAR
SHOWS ISOLATED SHOWERS OVER THE MARIANAS THIS AFTERNOON.

&&

.DISCUSSION...
LITTLE CHANGE WAS MADE TO THE FORECAST. UPPER-LEVEL TROUGH MOVING
OVER AREA WILL KEEP SHOWERS ISOLATED AT LEAST THROUGH MONDAY
NIGHT. MODELS HAVE REDUCED ANY RAINFALL MOVING TOWARDS THE
MARIANAS SO KEPT SHOWERS ISOLATED FROM TUESDAY THROUGH THE END OF
THE WEEK. THERE IS A SURFACE TROUGH AND CIRCULATION EAST OF 155E
THIS AFTERNOON. GFS HINTS AT IT MOVING WEST OF 150E BY WEDNESDAY
BUT BRINGS LITTLE RAIN WITH IT. WITH OTHER MODELS EITHER
DISCOUNTING THE TROUGH OR RAINFALL FIGURE ON LEAVING OUT ANY
SCATTERED SHOWERS UNTIL THINGS BECOME MORE DEFINITE.

&&

.MARINE...
EAST SWELL OF ONLY FOUR FEET IS EXPECTED THROUGH THE WEEK AND THE
IPAN BUOY OBSERVATIONS THIS AFTERNOON VERIFIED THIS WITH A SWELL
OF JUST LESS THAN FOUR FEET. THIS WILL KEEP SURF IN THE LOW RIP
CURRENT RISK ZONE THROUGH AT LEAST FRIDAY. DESPITE SUPER TYPHOON
MEGI SPINNING TO THE WEST OF THE LOCAL AREA BELIEVE THAT THE WIND
FIELD AND MOTION OF THE TYPHOON WILL LIMIT ANY MAJOR SWELL
PUSHING TOWARDS THE MARIANAS.

&&

.EASTERN MICRONESIA...
CONVECTION IS PRESENT ALONG A PRONOUNCED TRADE-WIND CONVERGENCE
ZONE AND A POSSIBLE EMBEDDED CIRCULATION OVER THE MARSHALLS. THE
CONVECTION IS EXPECTED TO CONTINUE DURING THE NEXT FEW DAYS BUT
WILL REMAIN NORTH OF MAJURO. ALL MODEL SOLUTIONS DEEPEN THE LOW
AND MOVE THIS FEATURE NORTHWESTWARD AWAY FROM THE MARSHALLS AS
THE WEEK PROGRESSES. RELATIVELY DRY SOUTHEAST TRADE-WIND FLOW
WILL PERSIST THROUGH MUCH OF THE WEEK FOR KOSRAE AND POHNPEI
BEFORE ANOTHER TROUGH PROPAGATES WESTWARD ALONG THE ITCZ AND
BEGINS TO AFFECT KOSRAE BY THE END OF THE WEEK.

&&

.WESTERN MICRONESIA...
LATEST VISIBLE IMAGERY AND ASCAT ANALYSIS SHOWS AN APPARENT
QUASI-STATIONARY WEAK CIRCULATION SOUTH OF THE MARIANAS. MOST OF
THE CONVECTIVE ACTIVITY ASSOCIATED WITH THIS FEATURE REMAINS WEST
OF CHUUK AND SOUTHEAST OF YAP. MODEL SOLUTIONS DIFFER IN FUTURE
INTENSITY OF THIS SYSTEM BUT FORECASTED MOVEMENT OF THIS FEATURE
IS FAIRLY CONSISTENT WITH ONLY A SLOW NORTHWESTWARD DRIFT PROGGED
TOWARD YAP. STRONG SHEAR SOUTH OF AN UPPER-LEVEL TROUGH MOVING
OVER THE EASTERN PHILIPPINE SEA SHOULD HINDER DEVELOPMENT OF THE
CIRCULATION DURING THE NEXT FEW DAYS. GIVEN THE EXPECTED
NORTHWESTWARD MOVEMENT OF THE CIRCULATION...MIDWEEK FORECAST FOR
YAP COULD CHANGE SIGNIFICANTLY BUT FORECAST CONFIDENCE REMAINS
FAIRLY LOW AT THIS POINT. FOR KOROR...CONVERGING WINDS SOUTH OF
SUPER TYPHOON MEGI SHOULD BRING SCATTERED SHOWERS TO THE AREA
BEGINNING LATE TONIGHT OR EARLY MONDAY BEFORE THE WEATHER DRIES
OUT SOMEWHAT BY MIDWEEK.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...NONE.
MARIANAS WATERS...NONE.
&&

$$

ZIOBRO/WILLIAMS

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